Battery pack

Abstract

The invention provides a battery pack. A battery pack is provided with: a battery module including a plurality of battery cells arranged in a first direction; and a case that accommodates two or more battery modules, in which the case includes: a case main body having a bottom portion and a side wall portion surrounding the periphery of the bottom portion; a cover body covering the opening of the case main body; and a partition plate that partitions the battery module disposed on the bottom portion side and the battery module disposed on the cover body side, one battery module being disposed between the partition plate and the bottom portion by fixing the partition plate to the side wall portion, and another battery module being disposed between the partition plate and the cover body.

Description

Technical Field

[0001] This technology relates to battery packs. Background Technology

[0002] Japanese Patent Application Publication No. 2023-012759 discloses a structure in which battery modules are arranged in two layers within the casing of a battery pack. By arranging the battery modules in two layers, the energy density of the battery pack is increased and its miniaturization is achieved.

[0003] There is a growing trend in the number of individual battery cells that make up the battery modules within battery packs. As a result, the weight of the battery modules also increases. Furthermore, the need to incorporate numerous support pillars within the casing to support the increased weight of the battery modules leads to a larger casing size. Consequently, this can become a significant factor hindering the improvement of battery pack energy density and miniaturization. Summary of the Invention

[0004] This technology was developed to address the aforementioned issues, with the aim of providing a battery pack with a structure that can suppress the enlargement of the housing by effectively utilizing the space within the housing.

[0005] This technology provides the following battery pack. [1]

[0007] A battery pack includes: a battery module comprising a plurality of battery cells arranged in a first direction; and a housing housing two or more of the battery modules, wherein the housing includes: a housing body having a bottom and a side wall portion surrounding the bottom; a cover covering an opening of the housing body; and a partition separating the battery modules disposed on the bottom side and the battery modules disposed on the cover side, wherein one battery module is disposed between the partition and the bottom by fixing the partition to the side wall portion, and other battery modules are disposed between the partition and the cover. [2]

[0009] In the battery pack described in [1], the sidewall portion includes a first sidewall portion located in a second direction orthogonal to the first direction and a second sidewall portion disposed opposite to the first sidewall portion. A first main step portion is provided on the first sidewall portion, and a second main step portion is provided on the second sidewall portion, wherein the partition plate is disposed between the first main step portion and the second main step portion. [3]

[0011] In the battery pack described in [1] or [2], the battery module includes a first end and a second end located in the first direction. A first support member is fixed at the first end, extending in a second direction orthogonal to the first direction and protruding from the end of the battery module at both ends. A second support member is fixed at the second end, extending in the second direction and protruding from the end of the battery module at both ends. For the battery module disposed on the bottom side between the partition plate and the bottom, the first support member and the second support member are fixed to the side wall. For the battery module disposed on the cover side between the partition plate and the cover, the first support member and the second support member are fixed to the partition plate. [4]

[0013] In the battery pack described in [3], the sidewall portion includes a first sidewall portion located in a second direction orthogonal to the first direction and a second sidewall portion disposed opposite to the first sidewall portion. For the battery module on the bottom side, one end of the first support member and one end of the second support member are fixed in the first sidewall portion, and the other end of the first support member and the other end of the second support member are fixed in the second sidewall portion. [5]

[0015] In the battery pack described in [4], two battery modules are arranged in the second direction on the bottom side. A bottom wall extending in the first direction is provided at the bottom between the two battery modules. The bottom wall fixes the other end of the first support member of one battery module and fixes the first end of the first support member of the other battery module. The bottom wall fixes the other end of the second support member of one battery module and fixes the second end of the second support member of the other battery module. The partition plate is fixedly supported on the bottom wall. [6]

[0017] In any of the battery packs described in [3] to [5], the sidewall portion includes a first sidewall portion located in a second direction orthogonal to the first direction and a second sidewall portion disposed opposite to the first sidewall portion. The partition plate has a main board disposed parallel to the bottom, a first sidewall plate located on one side of the first sidewall portion, and a second sidewall plate located on one side of the second sidewall portion. One end of the first support member and one end of the second support member are fixed to the first sidewall plate, and the other end of the first support member and the other end of the second support member are fixed to the second sidewall plate. [7]

[0019] In the battery pack described in [6], two battery modules are arranged in the second direction on the cover side. A partition wall extending in the first direction is provided between the two battery modules. The partition wall fixes the other end of the first support member of one battery module and fixes the other end of the first support member of the other battery module. The partition wall fixes the other end of the second support member of one battery module and fixes the other end of the second support member of the other battery module. [8]

[0021] In the battery pack described in [7], two battery modules are arranged on the bottom side in the second direction, and a bottom wall extending in the first direction is provided at the bottom between the two battery modules, and the partition wall is fixed to the bottom wall. [9]

[0023] In any of the battery packs described in [1] to [8], a bottom-side cooling component is disposed between the battery module and the bottom, and a partition-side cooling component is disposed between the battery module and the partition plate.

[0024] The above and other objects, features, aspects and advantages of the invention will become clear from the following detailed description of the invention in conjunction with the accompanying drawings. Attached Figure Description

[0025] Figure 1 This is a perspective view showing the structure of the battery pack according to the embodiment.

[0026] Figure 2 This is an exploded perspective view of the battery pack according to the implementation method.

[0027] Figure 3 yes Figure 1 Sectional view along line III-III.

[0028] Figure 4 yes Figure 1 Sectional view along line IV. Detailed Implementation

[0029] The following describes the implementation of this technology. Sometimes, the same or equivalent parts are labeled with the same reference numerals in the accompanying drawings, and their descriptions will not be repeated.

[0030] In the embodiments described below, when numbers, quantities, etc., are mentioned, the scope of this technology is not necessarily limited to those numbers, quantities, etc., unless specifically stated otherwise. In the embodiments described below, each constituent element is not necessarily essential to this technology unless specifically stated otherwise. This technology is not limited to performing all the effects mentioned in this embodiment.

[0031] In this specification, the terms "comprise," "include," and "have" are open-ended. That is, when a structure is included, other structures besides that structure may also be included, or none may be included.

[0032] In this specification, when using geometric terms and terms indicating positional and directional relationships, such as "parallel," "orthogonal," "45° oblique," "coaxial," and "along," these terms allow for manufacturing errors or slight variations. In this specification, when using terms indicating relative positional relationships such as "upper side" and "lower side," these terms are used to indicate the relative positional relationship in one state, and the relative positional relationship can be reversed or rotated to any angle depending on the setting direction of each mechanism (e.g., reversing the overall vertical orientation of the mechanism).

[0033] In this specification, "battery" is not limited to lithium-ion batteries, but may include other batteries such as nickel-metal hydride batteries and sodium-ion batteries. In this specification, the positive and negative electrodes are collectively referred to as "electrodes".

[0034] The "battery pack" in this manual can be installed in hybrid electric vehicles (HEVs), plug-in hybrid electric vehicles (PHEVs), and battery electric vehicles (BEVs). The purpose of the "battery pack" in this manual is not limited to vehicle use.

[0035] In the following description, the direction in which multiple battery cells are arranged within a single battery module is designated as the first direction (X direction in the figure). The battery modules are arranged side-by-side in the same plane. The direction orthogonal to the first direction (X direction in the figure) is designated as the second direction (Y direction in the figure), and the direction in which the battery modules are configured in two layers is designated as the third direction (Z direction in the figure). For ease of understanding, the dimensional ratios of the structures in the accompanying drawings are shown as altered from the actual dimensional ratios.

[0036] (Battery Pack 1)

[0037] Reference Figure 1 and Figure 2 The overall structure of the battery pack 1 will be described. The battery pack 1 includes: a battery module 20, which contains a plurality of battery cells 2 arranged in a first direction (X direction); and a housing 40, which houses two or more of the battery modules 20. The battery cells 2 have a square shape. The battery modules 20 are fixed together by means of connecting rods 20b, etc., to form a single unit.

[0038] In this embodiment, inside the housing 40, the battery modules 20 are arranged in two rows in the second direction (Y direction) and stacked in two layers in the third direction (Z direction), for a total of four battery modules 20 housed within the housing 40. Regarding the number of battery modules 20 housed in the housing 40, any structure with two layers of battery modules 20 stacked in the third direction (Z direction) is acceptable, and any number of battery modules 20 arranged in the second direction (Y direction) can be one or more.

[0039] Inside the housing 40, from bottom to top (as shown in the attached drawing), a bottom-side cooling component 50, two rows of battery modules 20, a partition plate 45, a partition plate-side cooling component 51, and two rows of battery modules 20 are housed. The opening 43a at the top of the housing 40 is closed by a cover 44. The cover 44 is fixed relative to the housing 40 using bolts or the like (not shown).

[0040] By fixing the partition plate 45 to the side wall portion 42 of the housing 40, one or more battery modules 20 are arranged between the partition plate 45 and the bottom 41, and one or more battery modules 20 are arranged between the partition plate 45 and the cover 44.

[0041] (Shell 40)

[0042] Reference Figure 2 and Figure 3 The specific structure of the housing 40 will be described. The housing 40 includes a housing body 43 and a cover 44. The housing body 43 has a bottom 41 and a side wall portion 42 surrounding the bottom 41. Inside the housing body 43, a partition plate 45 is arranged to separate the battery module 20 disposed on one side of the bottom 41 and the battery module 20 disposed on one side of the cover 44.

[0043] The sidewall portion 42 includes a first sidewall portion 42a located in a second direction (Y direction) orthogonal to the first direction (X direction) and a second sidewall portion 42b disposed opposite to the first sidewall portion 42a. Furthermore, the sidewall portion 42 includes a third sidewall portion 42c located in the first direction (X direction) and a fourth sidewall portion 42d disposed opposite to the third sidewall portion 42c.

[0044] In this embodiment, the bottom 41 is rectangular in shape, and the box-shaped shell body 43 is formed by providing a first side wall portion 42a, a second side wall portion 42b, a third side wall portion 42c, and a fourth side wall portion 42d in a manner that surrounds the bottom 41.

[0045] On the inner peripheral surface of the first side wall portion 42a, a first main step portion 42a1 for supporting the partition plate 45 is provided, extending in the first direction (X direction). On the inner peripheral surface of the second side wall portion 42b, a second main step portion 42b1 for supporting the partition plate 45 is provided, extending in the first direction (X direction).

[0046] In the region of the inner peripheral surface of the first side wall portion 42a that is close to the third side wall portion 42c, an 11th auxiliary step portion 42a11 is provided for mounting one end of the first support member 21 (described later). In the region of the inner peripheral surface of the first side wall portion 42a that is close to the fourth side wall portion 42d, a 12th auxiliary step portion 42a12 is provided for mounting one end of the second support member 22 (described later).

[0047] In the region of the inner circumferential surface of the second side wall portion 42b that is close to the third side wall portion 42c, a 21st auxiliary step portion 42b11 for supporting the other end of the first support member 21 is provided. In the region of the inner circumferential surface of the second side wall portion 42b that is close to the fourth side wall portion 42d, a 22nd auxiliary step portion 42b12 for supporting the other end of the second support member 22 is provided.

[0048] In this embodiment, a structure in which the battery modules 20 are arranged in two columns in the second direction (Y direction) is adopted. Therefore, a bottom wall 42e extending in the first direction (X direction) is provided at the bottom 41 between the two battery modules 20.

[0049] In the region of the bottom vertical wall 42e near the third side wall portion 42c, a third auxiliary step portion 42e11 is provided for supporting the other end of the first support member 21 and one end of the first support member 21. In the region of the bottom vertical wall 42e near the fourth side wall portion 42d, a third auxiliary step portion 42e12 is provided for supporting the other end of the second support member 22 and one end of the second support member 22.

[0050] (Separator 45)

[0051] Reference Figure 2 and Figure 3 The specific structure of the partition plate 45 will be described. The partition plate 45 serves to separate the battery module 20 disposed on one side (bottom side) of the bottom 41 and the battery module 20 disposed on one side (cover side) of the cover 44.

[0052] The partition plate 45 has a main plate 46 arranged parallel to the bottom 41, a first side wall plate 47 located on the side of the first side wall portion 42a, and a second side wall plate 48 located on the side of the second side wall portion 42b. The first side wall plate 47 and the second side wall plate 48 are erected relative to the main plate 46 and are arranged to extend along the first direction (X direction).

[0053] One end of the main board 46 is fixed to the first main step 42a1 provided on the first side wall 42a, and the other end of the main board 46 is fixed to the second main step 42b1 provided on the second side wall 42b. Thus, the partition plate 45 is arranged in such a way that it is erected between the first main step 42a1 and the second main step 42b1.

[0054] Specifically, on the first side wall plate 47, a plurality of bolt through holes BH1 are provided at predetermined intervals along the first direction (X direction), extending in the third direction (Z direction). At positions opposite to the bolt through holes BH1 on the first main step portion 42a1, a plurality of threaded holes BH2 are provided. By fastening bolts B1, which pass through the bolt through holes BH1, into the threaded holes BH2, one end of the main plate 46 is securely fixed to the first main step portion 42a1.

[0055] Similarly, on the second side panel 48, a plurality of bolt through holes BH1 extending in the third direction (Z direction) are provided at predetermined intervals along the first direction (X direction). A plurality of threaded holes BH2 are provided opposite to the bolt through holes BH1 on the second main step portion 42b1. By fastening bolts B1 that pass through the bolt through holes BH1 into the threaded holes BH2, the other end of the main plate 46 is securely fixed to the second main step portion 42b1.

[0056] In this embodiment, a structure is adopted in which the battery modules 20 are arranged in two columns in the second direction (Y direction). Therefore, a partition wall 49 extending in the first direction (X direction) is provided on the partition plate 45 between the two battery modules 20. Furthermore, the main board 46 of the partition plate 45 is fixedly supported on the bottom wall 42e.

[0057] Specifically, on the partition wall 49, a plurality of through holes BH1 for bolts are provided at predetermined intervals along the first direction (X direction) and extending in the third direction (Z direction). On the bottom wall 42e, at positions opposite to the through holes BH1 for bolts, a plurality of threaded holes BH2 are provided.

[0058] By fastening bolt B1, which passes through the partition plate vertical wall 49, to the threaded hole BH2 in the bottom vertical wall 42e, the main plate 46 of the partition plate 45 is fixedly supported on the bottom vertical wall 42e. By aligning the bottom vertical wall 42e with the partition plate vertical wall 49, the deflection of the main plate 46 can be suppressed, and the generation of vibration can be suppressed.

[0059] (Fixing structure of battery module 20)

[0060] The following is for reference Figure 2 and Figure 4 The fixing structure of battery module 20 will be described. Figure 4 The reference numerals shown in the accompanying drawings are mainly reference numerals indicating the structure of the third side wall portion 42c (the first end portion 21a side of the battery module 20), and the reference numerals in parentheses are reference numerals indicating the structure of the fourth side wall portion 42d (the second end portion 21b side of the battery module 20).

[0061] The battery module 20 includes a first end 21a and a second end 21b located in a first direction (X direction). At the first end 21a, a first support member 21 extending along a second direction (Y direction) orthogonal to the first direction (X direction) and protruding from the ends of the battery module 20 is fixed using bolts B3. At the second end 21b, a second support member 22 extending along the second direction (Y direction) and protruding from the ends of the battery module 20 is fixed.

[0062] (Fixing of the battery module 20 on the bottom side)

[0063] The bottom battery module 20 is fixed to the side wall 42 and the bottom vertical wall 42e using the first support member 21 and the second support member 22. Specifically, in the battery module 20 located on the left side of the figure, an 11th auxiliary step 42a11 is provided on the side of the third side wall 42c of the first side wall 42a. One end of the first support member 21 is fastened to the 11th auxiliary step 42a11 using bolt B2. The other end of the first support member 21 is fastened to the 31st auxiliary step 42e11 of the bottom vertical wall 42e using bolt B2. Threaded holes BH4 are provided in the 11th auxiliary step 42a11 and the 31st auxiliary step 42e11 respectively.

[0064] On one side of the fourth side wall 42d of the first side wall 42a, a 12th auxiliary step 42a12 is also provided. One end of the second support member 22 is fastened to the 12th auxiliary step 42a12 using bolt B2. The other end of the second support member 22 is fastened to the 32nd auxiliary step 42e12 of the bottom vertical wall 42e using bolt B2. Threaded holes BH4 are provided in both the 12th auxiliary step 42a12 and the 32nd auxiliary step 42e12.

[0065] In the battery module 20 located on the right side of the diagram, a 21st auxiliary step 42b11 is provided on one side of the third side wall 42c of the second side wall 42b. The other end of the first support member 21 is fastened to this 21st auxiliary step 42b11 using bolt B2. One end of the first support member 21 is fastened to the 31st auxiliary step 42e11 of the bottom vertical wall 42e using bolt B2. A threaded hole BH4 is provided in the 21st auxiliary step 42b11.

[0066] On one side of the fourth side wall 42d of the second side wall 42b, a 22nd auxiliary step 42b12 is also provided, and the other end of the second support member 22 is fastened to the 22nd auxiliary step 42b12 using bolt B2. One end of the second support member 22 is fastened to the 32nd auxiliary step 42e12 of the bottom vertical wall 42e using bolt B2. A threaded hole BH4 is provided in the 22nd auxiliary step 42b12.

[0067] The other end of the first support component 21 on the left and the first support component 21 on the right adopt a so-called socket joint structure, which does not produce a step difference. The two support components are fastened to the bottom wall 42e by a bolt B2.

[0068] In the above structure, the structure that supports both ends of the first support member 21 and the second support member 22 can also be placed on the upper surface of the first main step 42a1, the second main step 42b1 and the bottom vertical wall 42e.

[0069] (Fixing of battery module 20 on the cover side)

[0070] The battery module 20 on the cover side is fixed to the partition plate 45 using the first support member 21 and the second support member 22. Specifically, in the battery module 20 located on the left side of the figure, a first step portion 47a is provided on the side of the third side wall portion 42c of the first side wall plate 47, and one end of the first support member 21 is fastened to the first step portion 47a using bolt B2. A fifth step portion 49a is provided on the side of the third side wall portion 42c of the partition plate vertical wall 49, and the other end of the first support member 21 is fastened to the fifth step portion 49a using bolt B2. Threaded holes BH4 are provided in the first step portion 47a and the fifth step portion 49a respectively.

[0071] A second step 47b is provided on one side of the fourth side wall portion 42d of the first side wall panel 47, and one end of the second support member 22 is fastened to the second step 47b using bolt B2. A sixth step 49b is provided on one side of the fourth side wall portion 42d of the partition plate vertical wall 49, and the other end of the second support member 22 is fastened to the sixth step 49b using bolt B2. Threaded holes BH4 are provided in both the second step 47b and the sixth step 49b.

[0072] In the battery module 20 located on the right side of the diagram, a third step 48a is provided on the side of the third side wall portion 42c of the second side wall panel 48. The other end of the first support member 21 is fastened to this third step 48a using bolt B2. One end of the first support member 21 is fastened to the fifth step 49a of the partition plate vertical wall 49 using bolt B2. A threaded hole BH4 is provided in the third step 48a.

[0073] A fourth step 48b is provided on one side of the fourth side wall portion 42d of the second side wall panel 48, and the other end of the second support member 22 is fastened to the fourth step 48b using bolt B2. One end of the second side wall panel 48 is fastened to the sixth step 49b of the partition plate vertical wall 49 using bolt B2. A threaded hole BH4 is provided in the fourth step 48b.

[0074] The other end of the first support component 21 on the left and the first support component 21 on the right adopt a so-called socket joint structure, which does not produce a step difference. The two support components are fastened to the partition plate wall 49 by a bolt B2.

[0075] In the above structure, the structure that supports both ends of the first support member 21 and the second support member 22 can also be placed on the upper surface of the first side wall plate 47, the second side wall plate 48 and the partition wall 49.

[0076] By employing the aforementioned fixing structure of the battery module 20, a gap can be provided between the battery module 20 disposed on the bottom side and the bottom 41, and a bottom-side cooling component 50 can be disposed in this gap. Similarly, a gap can be provided between the battery module 20 disposed on the cover side and the main board 46, and a partition-side cooling component 51 can be disposed in this gap.

[0077] According to the battery pack 1 described above, a structure is adopted in which both ends of the partition plate 45 are fixed to the side wall portion 42 of the housing body 43. With this structure, the space inside the housing 40 can be effectively utilized, and the enlargement of the housing 40 can be suppressed.

[0078] In the above structure, the battery modules 20 are arranged in two columns in the second direction (Y direction) and stacked in two layers in the third direction (Z direction) as an example. However, even in the structure where the battery modules 20 are arranged in one or more columns in the second direction (Y direction) and stacked in three layers in the third direction (Z direction), the same effect as in this embodiment can still be obtained.

[0079] Embodiments of the present invention have been described, but the embodiments disclosed herein should be considered as illustrative in all respects and not restrictive. The scope of the invention is set forth in the claims and is intended to include all modifications of the same meaning and scope as the claims.

Claims

1. A battery pack comprising: a battery module including a plurality of battery cells arranged in a first direction; and a case housing two or more of the battery modules, wherein the case includes: a case main body having a bottom and a side wall portion surrounding a periphery of the bottom; a lid covering an opening of the case main body; and a partition plate separating the battery module disposed on one side of the bottom and the battery module disposed on one side of the lid, one of the battery modules is disposed between the partition plate and the bottom, and the other of the battery modules is disposed between the partition plate and the lid by fixing the partition plate to the side wall portion.

2. The battery pack according to claim 1, wherein the side wall portion includes a first side wall portion in a second direction orthogonal to the first direction and a second side wall portion disposed opposite to the first side wall portion, a first main step portion on which one end of the partition plate is placed is provided in the first side wall portion, a second main step portion on which the other end of the partition plate is placed is provided in the second side wall portion, and the partition plate is disposed so as to be bridged between the first main step portion and the second main step portion.

3. The battery pack according to claim 1, wherein the battery module includes a first end portion in the first direction and a second end portion, a first support member extending in a second direction orthogonal to the first direction and having both end portions protruding from the end portions of the battery module is fixed to the first end portion, a second support member extending in the second direction and having both end portions protruding from the end portions of the battery module is fixed to the second end portion, the first support member and the second support member are fixed to the side wall portion for the battery module disposed on the bottom side between the partition plate and the bottom, and the first support member and the second support member are fixed to the partition plate for the battery module disposed on the lid side between the partition plate and the lid.

4. The battery pack according to claim 3, wherein the side wall portion includes a first side wall portion in a second direction orthogonal to the first direction and a second side wall portion disposed opposite to the first side wall portion, one end portion of the first support member and one end portion of the second support member are fixed to the first side wall portion, and the other end portion of the first support member and the other end portion of the second support member are fixed to the second side wall portion for the battery module disposed on the bottom side.

5. The battery pack according to claim 4, wherein two of the battery modules are arranged in the second direction on the bottom side, a bottom standing wall extending in the first direction is provided in the bottom between the two battery modules, the other end portion of the first support member of one of the battery modules is fixed to the bottom standing wall, and one end portion of the first support member of the other of the battery modules is fixed. ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ the other end portion of the second support member of the battery module is fixed to the battery module on one side of the partition wall stand, and the one end portion of the second support member of the battery module is fixed to the battery module on the other side of the partition wall stand, the partition wall is fixed to the bottom stand.

6. The battery pack according to claim 3, wherein the side wall portion includes a first side wall portion in a second direction orthogonal to the first direction, and a second side wall portion disposed opposite to the first side wall portion, the partition wall has a main wall disposed parallel to the bottom, a first side wall disposed on one side of the first side wall portion, and a second side wall disposed on one side of the second side wall portion, the one end portion of the first support member and the one end portion of the second support member are fixed to the first side wall on one side of the first side wall portion, the other end portion of the first support member and the other end portion of the second support member are fixed to the first side wall on the other side of the first side wall portion.

7. The battery pack according to claim 6, wherein two battery modules are arranged in the second direction on the lid side, the partition wall stand extending in the first direction is provided between the two battery modules, the other end portion of the first support member of the battery module is fixed to the partition wall stand on one side, and the one end portion of the first support member of the battery module is fixed to the partition wall stand on the other side, the other end portion of the second support member of the battery module is fixed to the partition wall stand on one side, and the one end portion of the second support member of the battery module is fixed to the partition wall stand on the other side.

8. The battery pack according to claim 7, wherein two battery modules are arranged in the second direction on the bottom side, the bottom stand extending in the first direction is provided between the two battery modules, the partition wall stand is fixed to the bottom stand.

9. The battery pack according to claim 1, wherein a bottom side cooling member is disposed between the battery module and the bottom, a partition wall side cooling member is disposed between the battery module and the partition wall.

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